Today | Weather | Wednesday, November 4, 2026

Weather in Castle Rock, Colorado

07:25 AM
Now
Cloudy Weather
37° F
Feels Like 36°
Precipitation 0 %
Wind 6 mph
UV Index (0 - 11+) 0
Humidity 76 %
Today
Cloudy Weather
Day 55°
Night 30°
Precipitation 25 %
Wind 7 mph
UV Index (0 - 11+) 3

Castle Rock Weather Forecast Updated

50 seconds ago
Last updated on
Weather Forecast History
Last Year's Weather on This Day (November 4, 2025)
Cloudy Night

Day

72°

Night

36°

Wind

7 mph

Precipitation

0 %

Air Quality in Castle Rock

NOW
14 AQI
Good air quality Dominant pollutant: O3

Pollutant Concentrations:

PM2.5 1.75 µg/m³
PM10 1.92 µg/m³
O3 0.015 ppm
NO2 2.8 ppb
SO2 0 ppb
CO 0.13 ppm
NH3 0.54 µg/m³
NO 0.01 µg/m³
PM2.5 – Fine particles <2.5μm
PM10 – Inhalable particles <10μm
O3 – Ozone
NO2 – Nitrogen dioxide
SO2 – Sulfur dioxide
CO – Carbon monoxide
NH3 – Ammonia
NO – Nitric oxide

Health Recommendations:

Air quality is considered satisfactory, and air pollution poses little or no risk.

Show raw pollutant concentrations (µg/m³)
PM2.5 – 1.75 µg/m³
PM10 – 1.92 µg/m³
O3 – 28.76 µg/m³
NO2 – 5.21 µg/m³
SO2 – 0.02 µg/m³
CO – 146.05 µg/m³
NH3 – 0.54 µg/m³
NO – 0.01 µg/m³